PURPOSE: To shorten time required for sheet bundle discharge and thereby improve productivity by controlling the movement speed of a orderly depositing device when the sheet bundle is discharged so that said speed is lower than a movement speed at which the device returns to a standby home position after the discharge process.
CONSTITUTION: The subject sheet after-processing device is composed of a finish tray 40 on which a sheet bundle S can be deposited, side fences 103, 104 which are provided in movable manner in a direction crossing directly a direction where a sheet is transported and deposits a deposited sheet bundle in a direction crossing directly a direction of sheet transport, a stapler 301 which processes the deposited sheet bundle as specified, and a control part which controls the side fences 103, 104. The relationship between a movement speed V 1 at which the side fences 103, 104 moves from the standby position to the sheet bundle discharge position and the movement speed V 2 at which the side fences return to the standby position from the discharge position is controlled so that it is V 1 <V 2 . Subsequently, the miniaturization of an area for installing the device, cost reduction and the ameliorated simplicity of operation are ensured. At the same time, time required for the sheet bundle to be discharged can be reduced and thereby, the productivity can be improved.